Breastfed babies cry more, laugh less, and generally have “more challenging temperaments” than formula-fed infants, a study has found.
But such behaviour is normal, and mothers should learn to cope with it rather than reach for the bottle, according to researchers.
Infant irritability was said to be a natural part of the “dynamic communication” between mothers and babies.
Bottle-feeding was akin to “comfort eating” - producing quieter and apparently more content babies who may be over-nourished and putting on weight too rapidly.
The study rated the temperament of 316 babies at age three months using a 191-item behaviour questionnaire completed by their mothers.
Scores differed between babies that were exclusively breast-fed, bottle-fed or mixed-fed.
In three broad areas, breast and mixed-fed babies were rated as being more difficult to deal with than bottle-fed babies.
The study authors wrote in the online journal Public Library of Science ONE: “In particular, compared to formula-fed infants, breastfed infants were reported to show greater distress, less smiling, laughing and vocalisation, to be slower to calm down following distress or excitement, and more difficult to soothe by care givers.”
The findings may help explain why so many mothers give up on breastfeeding after a short time, despite the strong health message that “breast is best” for growing infants.
Department of Health guidelines say mothers should exclusively breastfeed their babies for the first six months after birth.
Janine Stockdale, research fellow at the Royal College of Midwives, said the study was small and more research was needed in the area before firm conclusions shuold be drawn.
She said: “It cannot be presumed that physical signalling by the baby automatically means it is hungry; other evidence suggests that babies engage in sucking behaviour called non-nutritive sucking. As breastfeeding mothers are often advised not to use a soother while their baby is learning to breastfeed, this means there is a need to look at babies’ behaviours, taking into consideration whether or not a soother was introduced.
“Factoring this type of information into the research would enable us to understand more about the suggested differences between the behaviours of breastfed and bottle fed babies.”
She added: “The evidence needs to be seen in a greater context before we start to draw conclusions on this research and we should continue to do all we can to promote and increase the rates of breastfeeding.”